This is the second edition of CSA C656, Performance standard for split-system and single-package central air conditioners and heat pumps.
It supersedes the previous edition, published in 1992 under the title Performance Standard for Single Package Central Air-Conditioners and Heat Pumps, and also replaces CAN/CSA-C273.3-M91, Performance Standard for Split-System Central Air-Conditioners and Heat Pumps.
This Standard applies to
(a) factory-made, air-source, air-sink, split-system, and single-package unitary air conditioners and heat pumps matching assemblies of the type classified in Clause 1.2 and intended for air-conditioning and space-heating applications in buildings;
(b) through-the-wall single-package split-system and small-duct high-velocity central air conditioners and heat pumps matching assemblies of the type classified in Clause 1.2 and intended for air-conditioning and space-heating applications in buildings;
(c) electrically driven, mechanical, vapour-compression-type systems charged with one of the refrigerants listed as Group 1 in CSA B52; and
(d) equipment rated below 19.0 kW (65 000 Btu/h) heating or cooling at standard rating conditions, in accordance with Clause 9.2.
This Standard does not apply to
(a) burner-assisted air-source heat pumps;
(b) air-source/air-sink multi-function heat pump systems; and
(c) integrated vapour-compression-type heat pump systems.
1.2 Unitary equipment
Unitary equipment within the scope of this Standard is outlined in Table 1.
In CSA Standards, shall is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; should is used to express a recommendation or that which is advised but not required; may is used to express an option or that which is permissible within the limits of the standard; and can is used to express possibility or capability. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.
1.4 Units of measurement
The values given in SI (metric) units are the standard. The values given in parentheses are for information only.